r - 推荐实验室，asMethod(object) 中的错误：dup_mMatrix_as_geMatrix 的类“NA”无效

Question

我正在尝试将矩阵更改为可以在推荐实验室包的功能中使用的结构。

datafile1 <- as(datafile1,"matrix")
datafile1
     name1 name2 rating1 rating2 rating3 rating4 rating5 rating6
[1,] "1"   "a"   "0"     "0"     "1"     "0"     "0"     "0"    
[2,] "2"   "d"   "0"     "0"     "1"     "0"     "0"     "0"    
[3,] "3"   "x"   "1"     "0"     "1"     "0"     "0"     "0"    
[4,] "4"   "b"   "0"     "1"     "1"     "0"     "0"     "0"  

library(recommenderlab)
datafile1 <- as(datafile1, "realRatingMatrix")

这是结果：

asMethod(object) 中的错误：dup_mMatrix_as_geMatrix 的类“NA”无效

有谁知道这里出了什么问题？

Answer 1

问题是RealRatingMatrix类 extends Matrix，并且Matrix没有实现其中包含characters 的矩阵。将您转换matrix为numeric第一个，然后转换。

# Recreate data
datafile1<-read.table(textConnection('
name1 name2 rating1 rating2 rating3 rating4 rating5 rating6
"1"   "a"   "0"     "0"     "1"     "0"     "0"     "0"    
"2"   "d"   "0"     "0"     "1"     "0"     "0"     "0"    
"3"   "x"   "1"     "0"     "1"     "0"     "0"     "0"    
"4"   "b"   "0"     "1"     "1"     "0"     "0"     "0"  
'),header=TRUE)
datafile1<-as.matrix(datafile1)

# Convert to numeric (by arbitrarily map the characters to numbers.)
datafile1<-sapply(data.frame(datafile1),as.numeric)

# Create real rating matrix
as(datafile1, "realRatingMatrix")
# 4 x 8 rating matrix of class ‘realRatingMatrix’ with 32 ratings.